Temperature and pressure controller



Dec. 26, 1.922. 1,439,750

A. J. NELSON.

TEMPERATURE. AND PRESSURE CONTROLLER.

FILED we. 28. 1919. 3 SHEETS-SHEET 2 0 3 5 T nl! E 9 1 m S Dec. 26, 1922.

A. J. NELSON. TEMPERATURE AND PRESSURE CONTROLLI-2R'l Fl LED Aus. 28, 191 9.

Il llllln Hm m IHHIHHHHW Hill Patented Det. 26, 1922.

PATENT oF'FlcE.

.ALBIN J. NELSON, 0F EAU CLAIRE, WISCONSIN.

TEMPERATURE AND PRESSURE CONTROLLER.

Application led August 28, 1919. Serial No. 320,388.

State 'of Wisconsin, have invented certain,

new and useful Improvements in Temperature and Pressure Controllers, of which the following, is a specification. A

My invention relates to improvements in controlling apparatus and althoughv capable of divergent application, `is particularly wellv 'adapted for the automatic control ofthe temperature or pressure of bodies of liquid or other fluid.

The principal objects of the invention are to provide temperature or pressure controlling apparatus which willbe inactive to reduce the maximum effect of the heat or pressure-supplying agent until substantially the temperature or pressure for which the controller is set has been attained; to providel an apparatus which will be, within the desired limits, extremely sensitive to slight changes of temperature, or pressure, to provide an eXp-ansible element lo-r diaphragm motor having a minimum'jfluid capacity and al maximum area to 4be acted on by said 'luid; to provide a construction which shall be self-compensating with respect to the efect of heat conveyed to the' apparatus by conduction or otherwise from the heating agent; to provide a construction having meansY for quickly and conveniently changing the ad'- justment; toprovide anv improved mechanical construction so organized that it may be assembled with a minimum of effort or troublesome manipulation", to provide an improved durable' and efficient construction which will maintain its adjustment indefinitely, whichl may be manufactured ata minimum cost while being simple 'in design and inexpensive to vmaintain and operate and in general to provide an improved 'controller construction of the character referred 1n the 'drawings accompanying this speciication I have illustrated my inventionpas applied to 'an apparatus for regulating or controlling the temperature of a tank heated by hot water or steam.l In the said drawings-- Fig. l is a vertical section through thet complete apparatus, certain parts being broken away, A

Flg. 2 is an end elevation of Fig. 1, minus he cipillary tube and bulb shown in Fig.

Fig 3 vis an enlargement of a portion of Flg. 1, but showing t-he expansible elements or mot-or actuated to control or regulate the tank temperature. v

, In the drawings, 10 designates as a Whole a controller bulb inserted in the desired location in the tank, theitemperature of which is `to be` controlled,vsaid bulbcontaining the usual supply ot' ether or other appropriate fluid, the vapors from which are conveyed to the motor byfmeans of a capillary tube 11. 12 represents iexible' armor by which .the capillary tube 11 is protected from damage or abuse.

The valve body 13 is interposed in the line used for supplying the heating' Huid to the tank which is being heated. Said Valve body is fitted with the appropriate balanced lor"other valve 14 which isllcontrolled by a vertical Valve stem 15 extending upwardly through a suitable stuiing box 16. The bonnet 17 of the valve body serves asa support for a frame which includes a bifurcated bracket vhaving arms l18 which support the motor housing 19 ofthe controller.- Said arms 18 lmay be formedorcast integrall with the motorhousing 19, which "thus constitutes an extension ofnsaid frame.

- The vupper endl of the motor housing 19 is closed'y by a demountable'- cap 20', the .cir-V cumference'of which ispengraved or otherwise4 markedYA with a suitablel scale 21, the flexible pointery 22- serving as an index by Awhich the device-may be s'et'to'the desired temperature. ,The actual adjustment of the 2 controller,- is eiected instantaneously by `means of aset screw'23 fitting a suitably tapped central hole drilledin the boss 24 of the cap, it being understood, that--the-upper vend of the- 'saidv screw 23 yis equipped with the usual insulated hand whee125. y'

'TheV lower end of the set screw 23 1s `pointed o-r coned and projects downwardly into a cylindrical vertical bore'26l formed the lower'or inner end of the boss 2 4, said cylindrical bore 26 serving as a guide for the upper stud 27 of the motor. 'The lower stud 28 of the motor is supported on the upper end of the valve stem 15, the exthe prope y time downward movement of the valve stem 15 to arrest or retard the flow of the heating fiuid.

It will be obse-rved that in the inactive position of the parts, as shown in Fig. 1 of the drawing, the stud 27 -is spaced from and does not contact with the point of the set screw 23. Also it will be seen that the valve 14 is open to its fullest extent. The valve is maintained in said fully open position by means of a compression spring 29 which engages a collar 30 fixed on the u per end of the valve stem 15 just below t e lower end of the stud 28. lt will be understood that the spring 29 is of amply sufficient capacity to raise'the Valve stem 15 against any frictional effect due to the valve stem gland or stufiing box 16. v

The lowerend ofthe compression spring 29l is supporte-d on the upper face of a Hanged flat annular plate 31 which constitutes the upper wall of a thermostatic chamber 32, the lower wall of which is formed by a fiexible flanged and corrugated diaphragm 33 into which the plate 31 is nested and secured by soldering or in any desired manner. The lower flexible wall 33 of the thermostatic chamber 32 is supported on a plate 34 which by means of a flange 35 and screws 36 is secured to the horizontal fiange 37 of a nipple 38. Said nipple 38 is internally threaded to screw over the lower end of a threaded tubular member 39, the upper end of which screws into a suitably threaded vertical aperture located centrally in plate 40 forming the lower wall of the motor housing 19.

1t will be observed that the spring 29 is effective to force the valve stem 15 u wardly to the point where the collar 30 wili)engage a fixed stop comprising -an internal shoulder 41 in the upper portion of the threaded tube 39, said tube being bored out internally of sufficient diameter to readily accommodate said coiled spring 29, and constituting a part of the frame. 1t will be manifest that the pres-sure of the spring 29 upon the top wall 31 of the thermostatic chamber 32 may be adjusted by rotating the flanged nipple 38 with reference to the stationary threaded supporting tube l39, such adjustmentI being for the purpose of regulating the compensating effect of the compensating thermostat 32, the function of which is to make the apparatus self-compensating to counteract the expansion or opening of the motor when filled with volatile Huid or vapor from the bulb 10 due to heat from the heating element being conducted into or radiated onto the diaphragm chambers comprising the motor. 1t will be understood that the cell or chamber 32 contains volatile fiuid having the necessary physical characteristics te secure the desired compensating effect under the conditions found 1n operation.

The diaphragm 'motor designated as a whole 42, consists of a series of cells or chambers, in the present instance four, communicating with each other througha central conduit 43, the upper end of which is connected' by means of a small transverse bore 44 with the coiled end 45'of the capillary tube 11. Said coiled ortion of the tube 11 constitutes a fiexiblld connection permitting free expansion of the motor. The cells or chambers are supported upon 'a rigid flanged bottom plate 46 on the lower sur` face ofwhich there is formed the stud 28 previously referred to. Each of the cells or chambers of the diaphragm motor 42 is constructed w-ith the usual corrugated 'annular -flexible metallic diaphragm 47 which co-operates with a su-perposed similarly corrugated upper plate 48, the diaphragm forming the lower wall of the diaphragm cell, and the top plate 48 constituting the upper wall. r1`he diaphragm ofthe bottom cell 49 of the series is imperforate and extends unbroken across the center of the supporting plate 46. Each of the diaphragms is flanged as shown at 50, the edge of the flan es being secured to the similarly flanged p ate 48 by means of solder or other means capableof making a hermetic seal.

r1`he construction of the main series of cells is such that, normally, the diaphragme 47 are in substantial contact with their cooperating top plates 48, the crevice between said parts constituting the cell. Hence the cubical content of the cell will be a minimum, while the full area of the c'ell is available for causing expansion, thereby insuring extremely sensitive and withal reliable operation. in assembling the cells the plates 48 is first nested in the diaphragm 47 and the fiange is soldered. 'A small thimble 51 whichfits a reduced upper extension or stud 52 projecting from the upper surface of a central-boss 53 on the plate 48 is then slipped into position over saidV stud. rl`he v diaphragm of the next cell which has been perforated lto fit loosely over-.the threads of the upper end of the thimble 51, is then placed in position and securely clamped by means of an annular lock nut 54 threaded onto the upper end of the thimble 51 and engaging the upper surface of the central portion of the diaphragm. rlhe parts 52, v-51 and 54 are then sweated together with solder so as to form a hermetic seal preventing the escape of volatile iiuid through the joint between the two cells. The upper plate or wall of the second or upper cell of the series is then nested within the fiange of the upper diaphragm and sealed in posit-ion after which the remaining units are assembled in a similar manner. The top plate 55` of the Series is formed with a substantial boss 56`on its lupper face, the stud 2 constituting an upperv extension of the said boss 5G. 'The Aend 45 of the capillary tube is soldered onto a lateral extension 5T of the said central boss 5G and connects with the lateral conduit 44 heretofore referred to'.

It' desired, in order to permit free Ipassage of volatile fluid into the cells from the centralconduit 43, the under sides of the disk plates 48 may begrooved out slightly as indicated at 58 in Fig. 3, although ordinaril)Y there will be no occasion for such a groove.

Vhen the heating flu-id commences to enter the tank which is'to be heatedthe parts are initially in the position shown in Fig. 1 with the valve stem 15 fully elevated and the valve 14 open to its maximum extent.4

This condition continues until substantially the desired temperature is reached for the reason that the vaporizing of the volatile fluid due to the increase of temperature in the tank simply causes the cells of the diaphragm motor to expand upwardly, downward movement being prevented by reason of the supporting .spring 29.

Except for the weight of the parts there is no tendency forthe lower end of the diaphragm motor to be depressed by the expansion ofthe cells until the stud 27 strikes the lower end of the set screw23. Thereafter for a short period there is no further expansion of the diaphragm motor until the temperature has increased suiiiciently to cause the expansive force to overcome the upward pressure of the spring 29. Until this time the collar 30 is .engaged with the shoulder 41` and the valveremains open to its fullest extent. rlhis is an extremely important feature in connection with my invention as it reduces considerably the time necessary to heat the tank or the body of fluid to the desired temperature for which the controller is set, regulation, i. e. diminution of the How of heat not occurring until the valve stem 15 commences to move downwardly.

lt will be understood that the various vparts or elements such as the flexibility of the diaphragms, the-strength of the spring physical .characteristics of which must be properlyadjusted for the particular control er-for which compensation is desired. The boss '60, through which'passes the I tube 11, is made as apart of the cap 2() so that said tube as well` as the motor may-be removed for repair or adjustment, or han dled for any other purpose, by 'merely taking off the cap. Thus, the valve-actuating `mechanism is not affected.

The described details of construction are merely illustrative of a specific application of my invention, the scope of which should be determined by reference to thel appended claims, the language of said claims to be construed as broadly as possible consistent with the state of the art.

I claim- 1. ln controlling apparatus, the combination of a How-regulating valve, a frame provided with a stop, a rod slidable in said iframe for actuating said valve, a spring for holding said rod in engagement with said stop, thereby to hold open said valve, an extension on the end of said frame remote from said valve, said extension being provided with a demountable part, forming with said extension an enclosure, and a diaphragm motor mounted in said enclosure and interposed between said demountable member and said rod for actuating the latter.

2. In controlling appara-tus, the combination of a flow-regulating Valve,a frame provided with a stop, a rod slidable in said lframe for actuating said valve, a spring for holding said rod in engagement with said lstop, thereby to hold open said valve, an extension on the end of said frame remote from said valve, said extension being provided with a demountable part, forming with said extension an enclosure., a diaphragm motor mounted in said enclosure and interposed between said demountable member and said rod for actuating the latter, and an adjustable member exteriorly operable carried by said demountable member for varying the amount of lost motion provided for said motor.

3. In controlling apparatus, the combination of flow-regulating means, a rod for actuating the same, a frame, means for normally holding said rod in engagement with a part of said frame, an expansible cell interposed between a part of said frame and said actuating rod for operating said rod, and when in released condition being out of contact with one of said parts and adapted to expand idly when initially actuated.

4. Inkcontrolling apparatus, the combination of flow-regulating means, a rod for actuating the same, a frame, means for normally holding said rod in engagement with a part of said frame, an expansible cell inter.

- posed between-a part of said frame and said actuating rod Y for A operating said rod and vwhen in released condition being out of contact with one of said last mentioned elements and adapted to expand idly When initially actuated, and an adjustable stop on one of -said elements for varying the amount otvlost motion.4 f

5. In apparatus ofthe class described 'the -combination of a How-regulating valve, a

frame, a valvefactuating rod slidably mounted in said frame, a` spring normally holding said valve in fully open position, an expansible element interposed between a portion of the frame and the end of said rod and being provided with lost motion, Whereby said element may expand without actuating said rod, and an adjusting screw for regulating the amount of said lost motion.

6. In combination, a flow-regulating valve, a slidable rod for actuating said valve, a frame within which said rod is slidable, an upper extension of said frame constituting a. casing, a diaphragm motor in said casing, said frame operating as a stop for the valve rod when the valve is fully-open, a spring for forcing said rod towards said stop, an adjusting screw in said casing substantially alined with said rod and exteriorly operated, and a diaphragm motor in said casing for actuating said rod, interposed between said screw `and said rod but normally not engaging one of said last named elements and capable of a substantial amount of free expansion before filling the space between said two elements.

7. In combination, a flow-regulating valve, a member for actuating the same, a frame provided with a stop, an element carried by said frame and arranged to actuate said member, a spring normally acting upon said member to hold the same against said stop against the action of said element, a support for said spring threadedly secured to said frame for adjusting the tension of said spring, and a compensating therlnostatic element interposed between said spring and said support.

8. In combination, a flow-regulating valve, a slidable rod for actuating said valve, a frame within which said rod is slidable, an upper extension of said frame constituting a closed casing, a diaphragm motor in said casing and engaging the upper end of said rod, said frame acting as a stop for the valve rod when the valve is fully open, and adjusting means in the upper end of said casing normally not engaging the motor when the latter is released but arranged to act as u Stop for the upper end of the same while the motor is operative, a spring surrounding said rod and engaging the latter to force the same against said frame, and an adjustable support for the lower end of said spring provided with a thermostatic element tor ad j usting the tension or" said Spring to compensate for heat conducted through said frame to the main expansion element.

ALBIN J. NELSGN. 

